Public roads were used as racetracks during an unofficial rally involving up to 300 cars in Bristol, police say.
Videos on social media apparently show cars being paraded and “wheel-spinning” along Ladies Mile on The Downs as crowds gathered to watch.
Stopping these sorts of gatherings is a “real challenge”, Avon and Somerset Police said.
No permission was sought for the event, at about 21:00 BST on Sunday, Bristol City Council said.
A spokesperson said: “We have assessed the damage caused by vehicles on the grass, which fortunately is not extensive and does not require intervention, and will continue to assist the police with their inquiries.”
Police responded to calls that cars were being driven dangerously on roads surrounding the Downs and said they “won’t allow public roads to be used a racetrack”.
Insp Rob Cheeseman, from Avon and Somerset Police, said preventing these sorts of events was a “real challenge” for officers.
“And that particularly lies around the secrecy of the event, particularly on where the location is going to be,” he said.
“That’s done on purpose to make sure they have every opportunity to set up their car meet before the police have the opportunity to disrupt it.”
Once police arrived they were able to move them “without using any legislation” and added no arrests were made.
The incident comes shortly after Bristol’s director of public health Christina Gray advised against gatherings of more than 30 people.
Ms Gray and deputy mayor Asher Craig issued a joint statement on 19 August asking people not to meet in large groups after a “small increase” in Coronavirus cases in the city.